Scalp acupuncture targets for neurological disorders：evidence from neuroimaging studies (part 2)

Scalp acupuncture is a method of treating diseases by dividing and stimulating the corresponding function-oriented cortical scalp areas. It is a commonly used therapy for neurological disorders. However, the specific target selection for scalp acupuncture remains to be explored. This manuscript aims to initiate an attempt to develop/identify scalp acupuncture targets based on neuroimaging findings and noninvasive brain stimulation.

Neurosynth-based meta-analysis of neuroimaging studies was conducted to identify brain stimulation targets of neurological disorders. The identified target regions were further projected to the scalp. The traditional acupoints and 10-20 EEG system were referenced for the localization of these targets. In this study, the "mild cognitive impairment" (MCI), "Alzheimer's disease" (AD) and "dementia" were used as the retrieval terms respectively, and a unity detection method was used to generate brain maps, with the default FDR (false discovery rate, P<0.01) threshold of Neurosynth set for subsequent exploration of various disease-related brain regions. The literature search was conducted on July 30, 2022.

The localization and manipulation suggestions of neuroimage-based scalp acupuncture targets for MCI, AD, and dementia were introduced in the present paper (part 2). Here are 3 target examples for each of these 3 diseases due to word limitation. 1) MCI：Based on the 81 papers retrieved, we identified 6 potential scalp acupuncture points for MCI, their corresponding brain regions, brain functions and the possible resultant effects of the scalp target acupoint stimulation respectively are as below. MCI1：the orbital part of the left inferior frontal gyrus (left Brodmann area ［BA］47), related to semantic coding, working memory and episodic memory, improving semantic coding and memory function；MCI2：the anterior motor area/left anterior central gyrus (left BA6), the motor center area, improving MCI motor function；MCI3：the left medial temporal gyrus (left BA21), related to the processing of speech, visual space, language and word understanding, improving language and memory. 2) AD：Based on the 196 papers retrieved, we found 6 potential scalp acupuncture targets for AD, their corresponding brain regions and brain functions of the 3 example targets respectively are as below. AD1：the left medial temporal gyrus (left BA21), participating in language and semantic processing, sentence and word generation, intent expression, deductive reasoning；AD2：the left angular gyrus (left BA39), related to semantic processing, word reading and comprehension, memory retrieval, attention and spatial cognition, reasoning, etc.；AD3：the left fusiform/suboccipital gyrus (left BA37), related to semantic classification, text generation, sign language, phonology processing, etc. 3) Dementia：Based on the 142 papers retrieved, we found 4 potential scalp acupuncture targets for dementia, their corresponding brain regions, brain functions and the possible targets of the proposed scalp stimulation respectively are as below. D1 and D2：the left inferior frontal gyrus (i.e., left BA46, and left BA47, respectively), being closely related to working memory, emotional response regulation, melody and other processing processes, may be suitable for treating memory decline and advanced executive dysfunction in patients with dementia；D3：the left medial temporal gyrus (left BA21), an important brain region for various sensory integration, cognitive processing and memory functions, and emotional processing, may be suitable for temporal dementia.

We identified scalp acupuncture targets for several common neurological disorders based on neuroimaging findings and noninvasive brain stimulation. The proposed targets may also be used for treating these disorders using nerve/brain stimulation methods.